Refactor rpmtests wrapper

Don't symlink rpmtests itself, we can run it directly from the
installation directory in the test tree.  This eliminates some extra
cd-ing.

No functional change.

tests/rpmtests.sh

@@ -1,21 +1,20 @@
 #!/bin/bash
 #
-# Wrapper for rpmtests that looks for atlocal in the script's directory instead
-# of $PWD or the one specified with -C.  In addition, implements the -L | --log
-# option to print the test log when done.
+# Wrapper around rpmtests that adds a couple of useful options/overrides:
+#   -C, --directory DIR
+#       like original -C but loads atlocal from script's directory if missing
+#   -L, --log
+#       print the test log when done
 
 SCRIPT_DIR=$(dirname $(readlink -f $0))
-SCRIPT_FILES="rpmtests atlocal mktree.common"
+SCRIPT_FILES="atlocal mktree.common"
 
-TARGET_DIR=$PWD
 PRINT_LOG=0
 
-cd "$SCRIPT_DIR"
-
 while [ $# != 0 ]; do
     case $1 in
         -C | --directory )
-            TARGET_DIR="$2"
+            cd "$2"
             shift
         ;;
         -L | --log )
@@ -28,15 +27,13 @@ while [ $# != 0 ]; do
     shift
 done
 
-# Symlink script files into $TARGET_DIR, prefer local versions though
+# Symlink script files into $PWD, prefer local versions though
 for file in $SCRIPT_FILES; do
-    [ -f "$TARGET_DIR/$file" ] || ln -s $PWD/$file $TARGET_DIR/
+    [ -f "$file" ] || ln -s $SCRIPT_DIR/$file .
 done
 
-cd "$TARGET_DIR"
-
 # Run the test suite
-./rpmtests "$@"; RC=$?
+$SCRIPT_DIR/rpmtests "$@"; RC=$?
 [ $PRINT_LOG == 1 ] && cat rpmtests.log
 
 # Clean up the symlinks