Fix gdb.base/print-file-var-main.c value check logic

Fix gdb.base/print-file-var-main.c value check logic

Fix a typo introduced in commit c56e7c4390ed ("Make ctxobj.exp and
print-file-var.exp work on all platforms.").

This doesn't really affect the outcome of the testcase.  I only
noticed the typo because I stepped through the program manually.

To avoid such problems if the test is extended, this moves the STOP
marker until after the program self-validates the values.  With the
typo in place, this alone would have resulted in a test FAIL.  I.e.,
it'd have caught the typo.

gdb/testsuite/ChangeLog:
2017-10-09  Pedro Alves  <palves@redhat.com>

	* gdb.base/print-file-var-main.c: Fix get_version_2 value check
	logic.  Move STOP marker after the value checks.
	* gdb.base/print-file-var.exp (continue to STOP marker): Tighten
	regexp.