Userland: Fix more compiler warnings.

Userland/allocate.cpp

@@ -13,7 +13,7 @@ enum Unit { Bytes, KiloBytes, MegaBytes };
 
 int main(int argc, char** argv)
 {
-    unsigned count = 50;
+    int count = 50;
     Unit unit = MegaBytes;
 
     if (argc >= 2) {

Userland/crash.cpp

@@ -55,6 +55,7 @@ int main(int argc, char** argv)
         volatile int lala = 10;
         volatile int zero = 0;
         volatile int test = lala / zero;
+        (void)test;
         ASSERT_NOT_REACHED();
     }
 
@@ -71,6 +72,7 @@ int main(int argc, char** argv)
     if (mode == ReadFromUninitializedMallocMemory) {
         auto* uninitialized_memory = (volatile dword**)malloc(1024);
         volatile auto x = uninitialized_memory[0][0];
+        (void)x;
         ASSERT_NOT_REACHED();
     }
 
@@ -78,6 +80,7 @@ int main(int argc, char** argv)
         auto* uninitialized_memory = (volatile dword**)malloc(1024);
         free(uninitialized_memory);
         volatile auto x = uninitialized_memory[4][0];
+        (void)x;
         ASSERT_NOT_REACHED();
     }
 

Userland/ls.cpp

@@ -57,7 +57,7 @@ int main(int argc, char** argv)
         return do_file_system_object_short(path);
     };
 
-    int status;
+    int status = 0;
     if (optind >= argc) {
         status = do_file_system_object(".");
     } else if (optind + 1 >= argc) {

Userland/sort.cpp

@@ -6,6 +6,9 @@
 
 int main(int argc, char** argv)
 {
+    UNUSED_PARAM(argc);
+    UNUSED_PARAM(argv);
+
     Vector<String> lines;
 
     for (;;) {

Userland/tail.cpp

@@ -68,12 +68,6 @@ off_t find_seek_pos(CFile& file, int wanted_lines)
     return pos;
 }
 
-static void exit_because_we_wanted_lines()
-{
-    fprintf(stderr, "Expected a line count after -n");
-    exit(1);
-}
-
 int main(int argc, char* argv[])
 {
     CArgsParser args_parser("tail");
@@ -108,8 +102,6 @@ int main(int argc, char* argv[])
     }
 
     bool flag_follow = args.is_present("f");
-    bool o_arg = args.is_present("o");
-
     auto pos = find_seek_pos(f, line_count);
     return tail_from_pos(f, pos, flag_follow);
 }