Fix linknamespace test handling of architecture-specific st_other.

For mips16, some of the linknamespace tests were failing because
[MIPS16] annotations in readelf output were wrongly interpreted as
falling in the symbol index field, meaning symbol index values were
wrongly interpreted as symbol names and such names as 1 and 2 then
resulted in namespace test failures.

This patch fixes this by removing the annotations for such
architecture-specific st_other bits before splitting the readelf
output into fields.  Tested for x86_64 and mips16.

	* conform/linknamespace.pl (list_syms): Remove \[.*?\] before
	splitting into fields.