Do not use __builtin_alloca in puts (could overflow the stack for large strings)

libs/libc/src/stdio.cpp

@@ -49,10 +49,8 @@ extern "C"
     }
     int puts(const char* s)
     {
-        size_t len = strlen(s);
-        char* output = (char*)__builtin_alloca(len + 1);
-        memcpy(output, s, len);
-        output[len] = '\n';
-        return syscall(SYS_write, output, len + 1);
+        long nwritten = syscall(SYS_write, s, strlen(s));
+        nwritten += syscall(SYS_write, "\n", 1);
+        return nwritten;
     }
 }