Fix bash in osx_cc_wrapper

RELNOTES: None.
PiperOrigin-RevId: 178745230

tools/cpp/osx_cc_wrapper.sh

diff --git a/tools/cpp/osx_cc_wrapper.sh b/tools/cpp/osx_cc_wrapper.sh
index 9438567..800bc05 100755
--- a/tools/cpp/osx_cc_wrapper.sh
+++ b/tools/cpp/osx_cc_wrapper.sh
@@ -84,6 +84,7 @@
 # Do replacements in the output
 for rpath in ${RPATHS}; do
     for lib in ${LIBS}; do
+        unset libname
         if [ -f "$(dirname ${OUTPUT})/${rpath}/lib${lib}.so" ]; then
             libname="lib${lib}.so"
         elif [ -f "$(dirname ${OUTPUT})/${rpath}/lib${lib}.dylib" ]; then

tools/cpp/osx_cc_wrapper.sh.tpl

diff --git a/tools/cpp/osx_cc_wrapper.sh.tpl b/tools/cpp/osx_cc_wrapper.sh.tpl
index 713c711..2df827a 100644
--- a/tools/cpp/osx_cc_wrapper.sh.tpl
+++ b/tools/cpp/osx_cc_wrapper.sh.tpl
@@ -86,6 +86,7 @@
 # Do replacements in the output
 for rpath in ${RPATHS}; do
     for lib in ${LIBS}; do
+        unset libname
         if [ -f "$(dirname ${OUTPUT})/${rpath}/lib${lib}.so" ]; then
             libname="lib${lib}.so"
         elif [ -f "$(dirname ${OUTPUT})/${rpath}/lib${lib}.dylib" ]; then