Fix typo to apply mac build workaround only on OSX (dotnet/coreclr#5988)

/init-tools.sh:72 tries to compare strings like this:
if [ "$OS"=="OSX" ]; then

What it actually does is different to what it looks like:
$ echo $OS
$ if [ "$OS"=="OSX" ]; then echo EQUAL; fi
EQUAL
$ if [ "$OS" == "OSX" ]; then echo EQUAL; fi
$

This commit fixes the typo and makes OSX workaround run on macs only.

Commit migrated from https://github.com/dotnet/coreclr/commit/422f37e2ee9eb7a8c5237811c12151072312cf12

diff --git a/src/coreclr/init-tools.sh b/src/coreclr/init-tools.sh
index 647eba6..0c56966 100755 (executable)
--- a/src/coreclr/init-tools.sh
+++ b/src/coreclr/init-tools.sh
@@ -69,7 +69,7 @@ esac
 initDistroName $OS
 
 # Work around mac build issue 
-if [ "$OS"=="OSX" ]; then
+if [ "$OS" == "OSX" ]; then
   echo Raising file open limit - otherwise Mac build may fail
   echo ulimit -n 2048
   ulimit -n 2048