Quick spelling update to man pages

Change-Id: Icd13bc19a59048ab9d90b6a55f68f052a0e2c4b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2797939
Commit-Queue: Dirk Pranke <dpranke@google.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>

man/html/git-squash-branch.html

@@ -769,7 +769,7 @@ commit. The new commit will contain a summary of all the commits which were
 squashed, preceded by a header message indicating that it’s the result of a
 squash (or the message you pass on the command line.).</p></div>
 <div class="paragraph"><p>Squashing branches is useful when trying to rebase-update over branches which
-were pushed to their upsteram (or committed by the <em>Commit Queue</em>), and then
+were pushed to their upstream (or committed by the <em>Commit Queue</em>), and then
 conflicting changes landed in upstream on top of the push/commit. If you know
 that your branch was committed but <a href="git-rebase-update.html">git-rebase-update(1)</a> isn&#8217;t able to
 automatically clean it, you can squash the troublesome branch before <code>git

man/man1/git-squash-branch.1

@@ -39,7 +39,7 @@ git-squash-branch \- Takes all commits in a single branch and replaces them with
 .sp
 git squash\-branch is a simple helper command\&. It takes all the commits on the current branch from the \fImerge_base\fR to HEAD, and reduces them to a single commit\&. The new commit will contain a summary of all the commits which were squashed, preceded by a header message indicating that it\(cqs the result of a squash (or the message you pass on the command line\&.)\&.
 .sp
-Squashing branches is useful when trying to rebase\-update over branches which were pushed to their upsteram (or committed by the \fICommit Queue\fR), and then conflicting changes landed in upstream on top of the push/commit\&. If you know that your branch was committed but \fBgit-rebase-update\fR(1) isn\(cqt able to automatically clean it, you can squash the troublesome branch before git rebase\-update, and then when git rebase\-update presents the conflict, you can verify that the conflict diff is what you expected (and then skip it with git rebase \-\-skip)\&.
+Squashing branches is useful when trying to rebase\-update over branches which were pushed to their upstream (or committed by the \fICommit Queue\fR), and then conflicting changes landed in upstream on top of the push/commit\&. If you know that your branch was committed but \fBgit-rebase-update\fR(1) isn\(cqt able to automatically clean it, you can squash the troublesome branch before git rebase\-update, and then when git rebase\-update presents the conflict, you can verify that the conflict diff is what you expected (and then skip it with git rebase \-\-skip)\&.
 .SH "OPTIONS"
 .PP
 \-m <message>, \-\-message=<message>

man/src/git-squash-branch.txt

@@ -21,7 +21,7 @@ squashed, preceded by a header message indicating that it's the result of a
 squash (or the message you pass on the command line.).
 
 Squashing branches is useful when trying to rebase-update over branches which
-were pushed to their upsteram (or committed by the 'Commit Queue'), and then
+were pushed to their upstream (or committed by the 'Commit Queue'), and then
 conflicting changes landed in upstream on top of the push/commit. If you know
 that your branch was committed but linkgit:git-rebase-update[1] isn't able to
 automatically clean it, you can squash the troublesome branch before `git