LoongArch: Use IS_ERR_PCPU() macro for KGDB

In commit a759e37 ("err.h: add ERR_PTR_PCPU(), PTR_ERR_PCPU() and
IS_ERR_PCPU() macros"), specialized macros were added to check an error
within a __percpu pointer, so use them instead of manually casting with
__force, like all other users of register_wide_hw_breakpoint().

Signed-off-by: Carlos López <clopez@suse.de>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Author: 00xc

arch/loongarch/kernel/kgdb.c

@@ -697,7 +697,7 @@ void kgdb_arch_late(void)
 			continue;
 
 		breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL, NULL);
-		if (IS_ERR((void * __force)breakinfo[i].pev)) {
+		if (IS_ERR_PCPU(breakinfo[i].pev)) {
 			pr_err("kgdb: Could not allocate hw breakpoints.\n");
 			breakinfo[i].pev = NULL;
 			return;