Fix uninitialised variable in some configs
diff --git a/library/ecp.c b/library/ecp.c
index 41bf03d..126e506 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -1914,6 +1914,8 @@
 #if MBEDTLS_ECP_FIXED_POINT_OPTIM == 1
     p_eq_g = ( mbedtls_mpi_cmp_mpi( &P->Y, &grp->G.Y ) == 0 &&
                mbedtls_mpi_cmp_mpi( &P->X, &grp->G.X ) == 0 );
+#else
+    p_eq_g = 0;
 #endif
 
     /* Pick window size and deduce related sizes */