hwrng: cleanup in hwrng_register()

My static checker complains that:

	drivers/char/hw_random/core.c:341 hwrng_register()
	warn: we tested 'old_rng' before and it was 'false'

The problem is that sometimes we test "if (!old_rng)" and sometimes we
test "if (must_register_misc)".  The static checker knows they are
equivalent but a human being reading the code could easily be confused.

I have simplified the code by removing the "must_register_misc" variable
and I have removed the redundant check on "if (!old_rng)".

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 3 insertions, 7 deletions

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index a0f7724852eb..cf49f1c88f01 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -302,7 +302,6 @@ err_misc_dereg:
 
 int hwrng_register(struct hwrng *rng)
 {
-        int must_register_misc;
         int err = -EINVAL;
         struct hwrng *old_rng, *tmp;
 
@@ -327,7 +326,6 @@ int hwrng_register(struct hwrng *rng)
                         goto out_unlock;
         }
 
-        must_register_misc = (current_rng == NULL);
         old_rng = current_rng;
         if (!old_rng) {
                 err = hwrng_init(rng);
@@ -336,13 +334,11 @@ int hwrng_register(struct hwrng *rng)
                 current_rng = rng;
         }
         err = 0;
-        if (must_register_misc) {
+        if (!old_rng) {
                 err = register_miscdev();
                 if (err) {
-                        if (!old_rng) {
-                                hwrng_cleanup(rng);
-                                current_rng = NULL;
-                        }
+                        hwrng_cleanup(rng);
+                        current_rng = NULL;
                         goto out_unlock;
                 }
         }