Fix ldbl-opt/w_lgamma_compatl.c libm_alias_ldouble_other usage.

Fix ldbl-opt/w_lgamma_compatl.c libm_alias_ldouble_other usage.

Testing with changes to enable _Float128 function aliases shows that
the libm_alias_ldouble_other usage in ldbl-opt/w_lgamma_compatl.c does
not in fact work.  Furthermore, it is unnecessary; the relevant
aliases get created through w_lgammal_compat2.c.  This patch removes
the problem code.

Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by the patch.  Also tested in conjunction with
patches to enable _Float128 function aliases.

	* sysdeps/ieee754/ldbl-opt/w_lgamma_compatl.c [BUILD_LGAMMA]:
	Remove conditional code.