[IA64] fix bug in ia64 __mutex_fastpath_trylock

The parenthesis around "likely" used in ia64 __mutex_fastpath_trylock
is incorrect, and it leads to broken mutex_trylock.  Here is the
patch that fixed the bug.  I removed the likely altogether because
there is no branch and gcc does a reasonable job at predicating the
return value.

Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>