ARM: 9022/1: Change arch/arm/lib/mem*.S to use WEAK instead of .weak

Commit d6d51a96 ("ARM: 9014/2: Replace string mem* functions for
KASan") add .weak directives to memcpy/memmove/memset to avoid collision
with KASAN interceptors.

This does not work with LLVM's integrated assembler (the assembly snippet
`.weak memcpy ... .globl memcpy` produces a STB_GLOBAL memcpy while GNU as
produces a STB_WEAK memcpy). LLVM 12 (since https://reviews.llvm.org/D90108)
will error on such an overridden symbol binding.

Use the appropriate WEAK macro instead.

Link: https://github.com/ClangBuiltLinux/linux/issues/1190
--

Fixes: d6d51a96 ("ARM: 9014/2: Replace string mem* functions for KASan")
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/lib/memcpy.S

@@ -58,10 +58,9 @@
 
 /* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
 
-.weak memcpy
 ENTRY(__memcpy)
 ENTRY(mmiocpy)
-ENTRY(memcpy)
+WEAK(memcpy)
 
 #include "copy_template.S"
 

arch/arm/lib/memmove.S

@@ -24,9 +24,8 @@
  * occurring in the opposite direction.
  */
 
-.weak memmove
 ENTRY(__memmove)
-ENTRY(memmove)
+WEAK(memmove)
 	UNWIND(	.fnstart			)
 
 		subs	ip, r0, r1

arch/arm/lib/memset.S

@@ -13,10 +13,9 @@
 	.text
 	.align	5
 
-.weak memset
 ENTRY(__memset)
 ENTRY(mmioset)
-ENTRY(memset)
+WEAK(memset)
 UNWIND( .fnstart         )
 	ands	r3, r0, #3		@ 1 unaligned?
 	mov	ip, r0			@ preserve r0 as return value