s390x: Mark archrandom.h functions __must_check

We must not use the pointer output without validating the
success of the random read.
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200110145422.49141-11-broonie@kernel.orgSigned-off-by: Theodore Ts'o <tytso@mit.edu>

arch/s390/include/asm/archrandom.h

@@ -21,17 +21,17 @@ extern atomic64_t s390_arch_random_counter;
 
 bool s390_arch_random_generate(u8 *buf, unsigned int nbytes);
 
-static inline bool arch_get_random_long(unsigned long *v)
+static inline bool __must_check arch_get_random_long(unsigned long *v)
 {
 	return false;
 }
 
-static inline bool arch_get_random_int(unsigned int *v)
+static inline bool __must_check arch_get_random_int(unsigned int *v)
 {
 	return false;
 }
 
-static inline bool arch_get_random_seed_long(unsigned long *v)
+static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
 {
 	if (static_branch_likely(&s390_arch_random_available)) {
 		return s390_arch_random_generate((u8 *)v, sizeof(*v));
@@ -39,7 +39,7 @@ static inline bool arch_get_random_seed_long(unsigned long *v)
 	return false;
 }
 
-static inline bool arch_get_random_seed_int(unsigned int *v)
+static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
 {
 	if (static_branch_likely(&s390_arch_random_available)) {
 		return s390_arch_random_generate((u8 *)v, sizeof(*v));