arch/x86/rdrand.c: Remove unneeded 'else'

'else' is not needed after a 'break' or 'return'.

Change-Id: Ib7bdefb0027a35de42f6a665b98f9e5a2791061f
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33331
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Vlado Cibic
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/arch/x86/rdrand.c

@@ -75,7 +75,6 @@ int get_random_number_64(uint64_t *rand)
 #if ENV_X86_64
 		if (rdrand_64(rand))
 			return 0;
-		else
 #endif
 		if (rdrand_32(&rand_high) && rdrand_32(&rand_low)) {
 			*rand = ((uint64_t)rand_high << 32) |