feat: small code optimisations

kernel/libc/stdlib.c

@@ -43,24 +43,21 @@ char *reverse(char *buffer, int i, int j) {
 }
 
 // Iterative function to implement itoa() function in C
-char *itoa(int value, char *buffer, int base) {
+char *itoa(uint32_t value, char *buffer, int base) {
     // invalid input
     if (base < 2 || base > 32)
         return buffer;
 
-    // consider absolute value of number
-    int n = abs(value);
-
     int i = 0;
-    while (n) {
-        int r = n % base;
+    while (value) {
+        uint32_t r = value % base;
 
         if (r >= 10)
             buffer[i++] = 65 + (r - 10);
         else
             buffer[i++] = 48 + r;
 
-        n = n / base;
+        value = value / base;
     }
 
     // if number is 0