[gdb/testsuite] Fix gdb.fortran/module.exp for debug info from other files

[gdb/testsuite] Fix gdb.fortran/module.exp for debug info from other files

On openSUSE Leap 15.1, I get:
...
FAIL: gdb.fortran/module.exp: info variables -n
...
because the info variables command prints info also for init.c:
...
File init.c:^M
24:     const int _IO_stdin_used;^M
...
while the regexps in the test-case only expect info for module.f90.

Fix this by extending the regexps.

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2019-10-17  Tom de Vries  <tdevries@suse.de>

	* gdb.fortran/module.exp: Allow info variables to print info for files
	other than module.f90.

Change-Id: I401d8018b121fc7343f6bc8b671900349462457f