Fix `error: expected string literal in 'asm'`.
This happens when compiling an ebpf object file that includes
`net/net_namespace.h` from linux kernel headers.

Include trace:
     include/net/net_namespace.h:10
     include/linux/workqueue.h:9
     include/linux/timer.h:8
     include/linux/debugobjects.h:6
     include/linux/spinlock.h:90
     include/linux/workqueue.h:9
     arch/arm64/include/asm/spinlock.h:9
     arch/arm64/include/generated/asm/qrwlock.h:1
     include/asm-generic/qrwlock.h:14
     arch/arm64/include/asm/processor.h:33
     arch/arm64/include/asm/kasan.h:9
     arch/arm64/include/asm/mte-kasan.h:45
     arch/arm64/include/asm/mte-def.h:14
Signed-off-by: Paul Semel <paul.semel@datadoghq.com>
Fixes: 2cb34276 ("arm64: kasan: simplify and inline MTE functions")
Cc: <stable@vger.kernel.org> # 5.12.x
Link: https://lore.kernel.org/r/bacb5387-2992-97e4-0c48-1ed925905bee@gmail.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>