gc.exp: Remove extraneous LD flags from the personality test

gc.exp: Remove extraneous LD flags from the personality test

Complement commit 8988502d7534 ("MIPS/LD/testsuite: Correct dynamic
links with VR4100, VR4300 and VR5000") and commit bf48520113c4 ("gc.exp:
Fix a typo: $LFLAGS -> $LDFLAGS"), and remove extraneous additional LD
flags explicitly passed to the personality test on invocation.  This
passing has accidentally leaked from a WIP version of the former change.

With the actual version committed the $LDFLAGS global variable is used
instead for `run_dump_test' to use implicitly, so that `-call_shared'
precedes `-lpersonality' on the linker's command line, as otherwise a
shared `libpersonality.so' library wouldn't be considered for linking,
causing the test to fail.

	ld/
	* testsuite/ld-gc/gc.exp: Remove extraneous LD flags from the
	personality test.