configure: force erroring out in check_disable_warning() if an option doesn't exists

Should prevent some options from being added to cflags when they
don't exist and the compiler only warns about it.
Reviewd-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>

configure

@@ -6370,9 +6370,14 @@ fi
 
 check_disable_warning(){
     warning_flag=-W${1#-Wno-}
-    test_cflags $warning_flag && add_cflags $1
+    test_cflags $unknown_warning_flags $warning_flag && add_cflags $1
 }
 
+test_cflags -Werror=unused-command-line-argument &&
+    append unknown_warning_flags "-Werror=unused-command-line-argument"
+test_cflags -Werror=unknown-warning-option &&
+    append unknown_warning_flags "-Werror=unknown-warning-option"
+
 check_disable_warning -Wno-parentheses
 check_disable_warning -Wno-switch
 check_disable_warning -Wno-format-zero-length