LoongArch: Make regs_irqs_disabled() more clear

In the current code, the definition of regs_irqs_disabled() is actually
"!(regs->csr_prmd & CSR_CRMD_IE)" because arch_irqs_disabled_flags() is
defined as "!(flags & CSR_CRMD_IE)", it looks a little strange.

Define regs_irqs_disabled() as !(regs->csr_prmd & CSR_PRMD_PIE) directly
to make it more clear, no functional change.

While at it, the return value of regs_irqs_disabled() is true or false,
so change its type to reflect that and also make it always inline.

Fixes: 803b0fc ("LoongArch: Add process management")
Signed-off-by: Tiezhu Yang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

Author: seehearfeel

arch/loongarch/include/asm/ptrace.h

@@ -33,9 +33,9 @@ struct pt_regs {
 	unsigned long __last[];
 } __aligned(8);
 
-static inline int regs_irqs_disabled(struct pt_regs *regs)
+static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
 {
-	return arch_irqs_disabled_flags(regs->csr_prmd);
+	return !(regs->csr_prmd & CSR_PRMD_PIE);
 }
 
 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)