pem: fix coverity uninitialised scalar variable.
Based on the value, it would with work properly or produce an error.  Most likely seems to have been the former.
@@ -323,7 +323,7 @@ EVP_PKEY *ossl_b2i_bio(BIO *in, int *ispub)
const unsigned char *p;
unsigned char hdr_buf[16], *buf = NULL;
unsigned int bitlen, magic, length;
- int isdss;
+ int isdss = -1;
void *key = NULL;
EVP_PKEY *pkey = NULL;
