xfstests: Fix test wildcard expansion.

xfstests: Fix test wildcard expansion.

Before commit 38d58591 "xfstests: fix typo in check",
check xfs/[0-9]?? would execute all tests/xfs/[0-9]?? because:

'if grep "^$testname" $group_file >/dev/null'
returns the contents of $group_file because $testname="".

Therefore xfs/[0-9]?? was echoed to $tmp.list

Change to use egrep to fix the parsing.

Signed-off-by: Rich Johnston <rjohnston@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>