[ATM] ambassador, firestream: "-1 >>" is implementation defined

6.5.7(5): The result of E1 >> E2 is E1 right-shifted E2 bit positions.
            ...
    If E1 has a signed type and a negative value, the resulting value
    is implementation defined.

So, cast -1 to unsigned type to make result well-defined.

[ Modified to use ~0U based upon recommendation from Al Viro. -DaveM ]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

drivers/atm/ambassador.c

@@ -978,7 +978,7 @@ static unsigned int make_rate (unsigned int rate, rounding r,
       }
       case round_up: {
 	// check all bits that we are discarding
-	if (man & (-1>>9)) {
+	if (man & (~0U>>9)) {
 	  man = (man>>(32-9)) + 1;
 	  if (man == (1<<9)) {
 	    // no need to check for round up outside of range

drivers/atm/firestream.c

@@ -511,7 +511,7 @@ static unsigned int make_rate (unsigned int rate, int r,
 		}
 		case ROUND_UP: {
 			/* check all bits that we are discarding */
-			if (man & (-1>>9)) {
+			if (man & (~0U>>9)) {
 				man = (man>>(32-9)) + 1;
 				if (man == (1<<9)) {
 					/* no need to check for round up outside of range */