[GAS][ARM] Fix testism for bl local v4t test

gas/ChangeLog
2018-11-23  Andre Vieira  <andre.simoesdiasvieira@arm.com>

	* testsuite/gas/arm/bl-local-v4t.d: Remove
	warning check.
	* testsuite/gas/arm/blx-local-thumb.s: New.
	* testsuite/gas/arm/blx-local-thumb.d: New.