random: move random_min_urandom_seed into CONFIG_SYSCTL ifdef block

Building arm allnodefconfig causes the following build warning:

drivers/char/random.c:318:12: warning: 'random_min_urandom_seed' defined but not used [-Wunused-variable]

Fix the warning by moving 'random_min_urandom_seed' declaration inside
the CONFIG_SYSCTL ifdef block, where it is actually used.

While at it, remove the comment prior to the variable declaration.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

drivers/char/random.c

@@ -312,11 +312,6 @@ static int random_read_wakeup_bits = 64;
  */
 static int random_write_wakeup_bits = 28 * OUTPUT_POOL_WORDS;
 
-/*
- * Variable is currently unused by left for user space compatibility.
- */
-static int random_min_urandom_seed = 60;
-
 /*
  * Originally, we used a primitive polynomial of degree .poolwords
  * over GF(2).  The taps for various sizes are defined below.  They
@@ -1886,6 +1881,7 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
 static int min_read_thresh = 8, min_write_thresh;
 static int max_read_thresh = OUTPUT_POOL_WORDS * 32;
 static int max_write_thresh = INPUT_POOL_WORDS * 32;
+static int random_min_urandom_seed = 60;
 static char sysctl_bootid[16];
 
 /*