Documentation/x86: Fix path to entry_32.S

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20190520205253.23762-1-ira.weiny@intel.com


[ Adjusted the patch to the RST conversion. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>