Fix typo in cosmocc (#884)

Author: ahgamut

bin/cosmocc

@@ -180,7 +180,7 @@ if [ ! -d "$COSMO" ]; then
 fi
 
 if [ "$1" = "--update" ]; then
-  cd /opt/cosmo || exit
+  cd $COSMO || exit
   if GIT=$(command -v git); then
     echo "running git pull on cosmo..." >&2
     "$GIT" pull --quiet || exit

bin/fatcosmocc

@@ -149,7 +149,7 @@ else
 fi
 
 if [ "$1" = "--update" ]; then
-  cd /opt/cosmo || exit
+  cd $COSMO || exit
   if GIT=$(command -v git); then
     echo "running git pull on cosmo..." >&2
     "$GIT" pull --quiet || exit