Coverity fixes

[paulidale]

Fixes for recent Coverity issues:

• 1463571: Null pointer dereferences (FORWARD_NULL)
• 1463574: Null pointer dereferences (REVERSE_INULL)
• 1463576: Error handling issues (CHECKED_RETURN)
• 1463258: Incorrect expression (EVALUATION_ORDER)

[kroeckx]

Should that be REVERSE_NULL, without the I?

[paulidale]

It was a copy paste from the Coverity issue, so I guess it is correct.

I'm not sure what REVERSE_INULL means.

** CID 1463574:  Null pointer dereferences  (REVERSE_INULL)
/providers/implementations/keymgmt/rsa_kmgmt.c: 516 in rsa_gen()


________________________________________________________________________________________________________
*** CID 1463574:  Null pointer dereferences  (REVERSE_INULL)
/providers/implementations/keymgmt/rsa_kmgmt.c: 516 in rsa_gen()
510             break;
511         default:
512             /* Unsupported RSA key sub-type... */
513             return NULL;
514         }
515     
   CID 1463574:  Null pointer dereferences  (REVERSE_INULL)
   Null-checking "gctx" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
516         if (gctx == NULL
517             || (rsa_tmp = rsa_new_with_ctx(gctx->libctx)) == NULL)
518             return NULL;
519     
520         gctx->cb = osslcb;
521         gctx->cbarg = cbarg;

[t8m]

It could mean 'is NULL'.

[paulidale]

Merged to master, thanks for the review.