[fix: target check_tools]
[fix: target check_tools]

	issue: check_tools only caused a make error if the last checked
		   tool is not valid
	reason: the shell loop did not return on error, but returned the
		    the result value of the last tool check
	fix: check individual return values for tool checks

jnow-87/vimgdb,jnow-87/vimgdb,jnow-87/vimgdb