s390: fix unrecognized __aligned() in uapi header

__aligned() is a shorthand that is only available in the kernel space
because it is defined in include/linux/compiler_attributes.h, which is
not exported to the user space.

Detected by compile-testing exported headers.

./usr/include/asm/runtime_instr.h:60:37: error: expected declaration specifiers or ‘...’ before numeric constant
 } __attribute__((packed)) __aligned(8);
                                     ^
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

arch/s390/include/uapi/asm/runtime_instr.h

@@ -57,7 +57,7 @@ struct runtime_instr_cb {
 	__u64 sf;
 	__u64 rsic;
 	__u64 reserved8;
-} __packed __aligned(8);
+} __attribute__((__packed__, __aligned__(8)));
 
 static inline void load_runtime_instr_cb(struct runtime_instr_cb *cb)
 {