Update rnglib std variant to stdint

It appears since CI only builds linux and windows variants of the
rnglib, the std variant was left behind on the conversion to stdint
types.

Signed-off-by: Abe Kohandel <abe.kohandel@intel.com>

Author: Abe Kohandel

os_stub/rnglib/rng_std.c

@@ -19,21 +19,21 @@
  * @retval false        Failed to generate the random number.
  *
  **/
-bool libspdm_get_random_number_64(uint64 *rand_data)
+bool libspdm_get_random_number_64(uint64_t *rand_data)
 {
-    uint8 *ptr;
+    uint8_t *ptr;
 
     assert(rand_data != NULL);
 
-    ptr = (uint8 *)rand_data;
-    ptr[0] = (uint8)rand();
-    ptr[1] = (uint8)rand();
-    ptr[2] = (uint8)rand();
-    ptr[3] = (uint8)rand();
-    ptr[4] = (uint8)rand();
-    ptr[5] = (uint8)rand();
-    ptr[6] = (uint8)rand();
-    ptr[7] = (uint8)rand();
+    ptr = (uint8_t *)rand_data;
+    ptr[0] = (uint8_t)rand();
+    ptr[1] = (uint8_t)rand();
+    ptr[2] = (uint8_t)rand();
+    ptr[3] = (uint8_t)rand();
+    ptr[4] = (uint8_t)rand();
+    ptr[5] = (uint8_t)rand();
+    ptr[6] = (uint8_t)rand();
+    ptr[7] = (uint8_t)rand();
 
     return true;
 }