[build] Fix formatting in BUILD.gn

git cl format flagged this while merging

Review-Url: https://codereview.chromium.org/2594693003
Cr-Commit-Position: refs/heads/master@{#41875}

BUILD.gn

@@ -890,9 +890,9 @@ v8_source_set("v8_base") {
     "src/asmjs/asm-wasm-builder.h",
     "src/asmjs/switch-logic.cc",
     "src/asmjs/switch-logic.h",
+    "src/assembler-inl.h",
     "src/assembler.cc",
     "src/assembler.h",
-    "src/assembler-inl.h",
     "src/assert-scope.cc",
     "src/assert-scope.h",
     "src/ast/ast-expression-rewriter.cc",