gen_path_callouts: Fix usage string

The code had a string concat operator '.' instead of a ';'.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I4bf77d4eb639558882e904925920aa6e068a52e9
diff --git a/gen_path_callouts.pl b/gen_path_callouts.pl
index c49524f..74da21d 100755
--- a/gen_path_callouts.pl
+++ b/gen_path_callouts.pl
@@ -835,6 +835,6 @@
     print "$0 -m <MRW file> -o <Output filename> [--segments] [-n]\n" .
     "        -m <MRW file> = The MRW XML\n" .
     "        -o <Output filename> = The output JSON\n" .
-    "        [--segments] = Optionally create a segments.json file\n" .
+    "        [--segments] = Optionally create a segments.json file\n";
     exit(1);
 }