devtools: fix regex in symbol addition check

devtools: fix regex in symbol addition check

The regex to determine the end of the map file chunk in a patch seems to
be wrong,  It was using perl regex syntax, which awk doesn't appear to
support (I'm still not sure how it was working previously).  Regardless,
it wasn't triggering and as a result symbols were getting added to the
mapdb that shouldn't be there.

Fix it by converting the regex to use traditional posix syntax, matching
only on the negation of the character class [^map]

Tested and shown to be working on the ip_frag patch set provided by
doucette@bu.edu

Fixes: 4bec48184e33 ("devtools: add checks for ABI symbol addition")
Cc: stable@dpdk.org
Reported-by: Cody Doucette <doucette@bu.edu>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>