MIPS: jump_label: Fix compat branch range check

Cast upper bound of branch range to long to do signed compare,
avoid negative offset trigger this warning.

Fixes: 9b6584e35f40 ("MIPS: jump_label: Use compact branches for >= r6")
Signed-off-by: Jiaxun Yang <[e-mail]>
Cc: [e-mail]
Reviewed-by: Philippe Mathieu-Daudé <[e-mail]>
Signed-off-by: Thomas Bogendoerfer <[e-mail]>

arch/mips/kernel/jump_label.c

···
 			 * The branch offset must fit in the instruction's 26
 			 * bit field.
 			 */
-			WARN_ON((offset >= BIT(25)) ||
+			WARN_ON((offset >= (long)BIT(25)) ||
 				(offset < -(long)BIT(25)));
 
 			insn.j_format.opcode = bc6_op;