Remove preprocessor directive from log macro calls.

Preprocessor directives inside macro calls, such as the new log macros,
are undefined behaviour and do not work with, eg old GCCs.  Put the
entire log call inside the ifdef for OPENSSL_HAS_NISTP521.

ssh-keygen.c

@@ -219,10 +219,11 @@ type_bits_valid(int type, const char *name, u_int32_t *bitsp)
 		break;
 	case KEY_ECDSA:
 		if (sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
-			fatal("Invalid ECDSA key length: valid lengths are "
 #ifdef OPENSSL_HAS_NISTP521
+			fatal("Invalid ECDSA key length: valid lengths are "
 			    "256, 384 or 521 bits");
 #else
+			fatal("Invalid ECDSA key length: valid lengths are "
 			    "256 or 384 bits");
 #endif
 	}