crypto: ccp - avoid uninitialized variable warning

The added support for version 5 CCPs introduced a false-positive
warning in the RSA implementation:

drivers/crypto/ccp/ccp-ops.c: In function 'ccp_run_rsa_cmd':
drivers/crypto/ccp/ccp-ops.c:1856:3: error: 'sb_count' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This changes the code in a way that should make it easier for
the compiler to track the state of the sb_count variable, and
avoid the warning.

Fixes: 6ba46c7d4d7e ("crypto: ccp - Fix base RSA function for version 5 CCPs")
Signed-off-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Gary R Hook <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/crypto/ccp/ccp-ops.c

···
 	o_len = 32 * ((rsa->key_size + 255) / 256);
 	i_len = o_len * 2;
 
+	sb_count = 0;
 	if (cmd_q->ccp->vdata->version < CCP_VERSION(5, 0)) {
 		/* sb_count is the number of storage block slots required
 		 * for the modulus.
···
 	ccp_dm_free(&exp);
 
 e_sb:
-	if (cmd_q->ccp->vdata->version < CCP_VERSION(5, 0))
+	if (sb_count)
 		cmd_q->ccp->vdata->perform->sbfree(cmd_q, op.sb_key, sb_count);
 
 	return ret;