[tsan][go] Fix string equal operator

Fixed error
```
compiler-rt/lib/tsan/go/buildgo.sh: 62: [: unexpected operator
```

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D135537

GitOrigin-RevId: 50312ea133999cb2aad1ab9ef0ec39429a9427c5
diff --git a/lib/tsan/go/buildgo.sh b/lib/tsan/go/buildgo.sh
index a53bd0f..fcb102c 100755
--- a/lib/tsan/go/buildgo.sh
+++ b/lib/tsan/go/buildgo.sh
@@ -59,7 +59,7 @@
 		ARCHCFLAGS="-m64 -mcpu=power8 -fno-function-sections"
 	elif [ "`uname -a | grep x86_64`" != "" ]; then
 		SUFFIX="linux_amd64"
-		if [ "$GOAMD64" == "v3" ]; then
+		if [ "$GOAMD64" = "v3" ]; then
 			ARCHCFLAGS="-m64 -msse4.2"
 		else
 			ARCHCFLAGS="-m64 -msse3"