Utilities: Report correct memory addresses for pmap

While I think negative memory might be an interesting concept to
investigate I don't think we're quite ready for it yet:

7ca71000        8192 r-xs-  libcrypt.so: .text
7ca73000        4096 r----  libcrypt.so: .relro
7ca74000        4096 rw---  libcrypt.so: .data
-6d391000       45056 r-xs-  libttf.so: .text
-6d385000        4096 r----  libttf.so: .relro
-6d384000        4096 rw---  libttf.so: .data

Userland/Utilities/pmap.cpp

@@ -60,7 +60,7 @@ int main(int argc, char** argv)
 
     for (auto& value : sorted_regions) {
         auto& map = value.as_object();
-        auto address = map.get("address").to_int();
+        auto address = map.get("address").to_uint();
         auto size = map.get("size").to_string();
 
         auto access = String::formatted("{}{}{}{}{}",