* config/h8300/h8300-protos.h: Update the prototype of
	output_a_shift.
	* config/h8300/h8300.c (output_a_shift): Remove an unused
	argument 'insn'.  Remove redundant code.
	* config/h8300/h8300.md: Adust to the new prototype of
	output_a_shift.

From-SVN: r49310