Fix msp430 build with gcc-5

[Alan Modra]

gcc-5 correctly complains "loop exit may only be reached after
undefined behavior".  I was going to correct this by checking the
index before dereferencing the array rather than the other way around,
but then I noticed it is possible for extract_cmd to write the
terminating zero one past the end of "cmd".  Fixing that means no
index check is needed in md_assemble (and we do need "cmd" to be zero
terminated).

	* config/tc-msp430.c (md_assemble): Correct size passed to
	extract_cmd.  Remove index check.

diff --git a/gas/config/tc-msp430.c b/gas/config/tc-msp430.c
index e44e7b2..2891c13 100644
--- a/gas/config/tc-msp430.c
+++ b/gas/config/tc-msp430.c
@@ -3174,9 +3174,9 @@ md_assemble (char * str)
   unsigned int i = 0;
 
   str = skip_space (str);	/* Skip leading spaces.  */
-  str = extract_cmd (str, cmd, sizeof (cmd));
+  str = extract_cmd (str, cmd, sizeof (cmd) - 1);
 
-  while (cmd[i] && i < sizeof (cmd))
+  while (cmd[i])
     {
       char a = TOLOWER (cmd[i]);
       cmd[i] = a;

-- 
Alan Modra
Australia Development Lab, IBM