Fix style

Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/library/bignum.c b/library/bignum.c
index 08b8b34..0e3eb4b 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -1628,7 +1628,7 @@
      * Allocate working memory for mbedtls_mpi_core_exp_mod()
      */
     size_t T_limbs = mbedtls_mpi_core_exp_mod_working_limbs(N->n, E->n);
-    mbedtls_mpi_uint *T = (mbedtls_mpi_uint*) mbedtls_calloc(T_limbs, sizeof(mbedtls_mpi_uint));
+    mbedtls_mpi_uint *T = (mbedtls_mpi_uint *) mbedtls_calloc(T_limbs, sizeof(mbedtls_mpi_uint));
     if (T == NULL) {
         return MBEDTLS_ERR_MPI_ALLOC_FAILED;
     }