test/vmd: fix 'if' syntax error

Fixing errors reported by ShellCheck:
SC1009: The mentioned syntax error was in this if expression.
SC1073: Couldn't parse this test expression. Fix to allow more checks.
SC1019: Expected this to be an argument to the unary condition.
SC1020: You need a space before the ].
SC1072: Missing space before ]. Fix any mentioned problems and try again.

Removing mentioned errors from check_format.sh exlusion list, as
all of these errors should be tested for regularly.

Change-Id: I19402baba7bb8e59ed707de97133bd0a579333cf
Signed-off-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/463174


Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>