In r262961 I only updated the out-of-line copy of ceil_log2.  This patch
applies the same change to the other (inline) one.

2018-07-30  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	PR tree-optimization/86506
	* hwint.h (ceil_log2): Resync with hwint.c implementation.

From-SVN: r263064