LU-6210 tests: Change positional struct initializers to C99

LU-6210 tests: Change positional struct initializers to C99

This patch makes no functional changes.  Struct initializers in the
tests directory that use C89 or GCC-only syntax are updated to C99
syntax.

The C99 syntax prevents incorrect initialization if values are
accidently placed in the wrong position, allows changes in the struct
definition, and clears any members that are not given an explicit
value.

The following struct initializers have been updated:

lustre/tests/checkfiemap.c:
	struct option long_opts[]
lustre/tests/llapi_layout_test.c:
	static struct test_tbl_entry test_tbl[]
lustre/tests/mcreate.c:
	struct option opts[]
lustre/tests/mmap_sanity.c:
	struct test_case tests[]
lustre/tests/mpi/mdsrate.c:
	struct option longOpts[]
lustre/tests/statmany.c:
	struct option longopts[]

Test-Parameters: trivial
Signed-off-by: Steve Guminski <stephenx.guminski@intel.com>
Change-Id: Iadc141507664c97dcc3112c382d4e379a1bf8041
Reviewed-on: https://review.whamcloud.com/23568
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Frank Zago <fzago@cray.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>