Linux buildbot fix: detect swig tool from PATH in shell script (before searching hardcoded directories)



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@168831 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/scripts/build-swig-wrapper-classes.sh b/scripts/build-swig-wrapper-classes.sh
index ed3f8f7..d15af40 100755
--- a/scripts/build-swig-wrapper-classes.sh
+++ b/scripts/build-swig-wrapper-classes.sh
@@ -83,8 +83,8 @@
 # Next look for swig
 #
 
-SWIG=
-if [ -f /usr/bin/swig ]
+SWIG=`which swig`
+if [ ! -x "$SWIG" -a -f /usr/bin/swig ]
 then
     SWIG=/usr/bin/swig
 else