Remove 4 cppcheck suppressions reported unmatched.

src/common.h

@@ -670,7 +670,7 @@ ssize_t read_loop(int fd, void *buff, size_t count);
 ///
 /// will print the string 'fish: Pi = 3.141', given that debug_level is 1 or higher, and that
 /// program_name is 'fish'.
-void __attribute__((noinline)) debug(int level, const char *msg, ...);
+void __attribute__((noinline)) debug(int level, const char *msg, ...) __attribute__ ((format (printf, 2, 3)));
 void __attribute__((noinline)) debug(int level, const wchar_t *msg, ...);
 
 /// Replace special characters with backslash escape sequences. Newline is replaced with \n, etc.

src/complete.cpp

@@ -1372,7 +1372,6 @@ void complete(const wcstring &cmd_with_subcmds, std::vector<completion_t> *out_c
                 }
             }
 
-            // cppcheck-suppress nullPointerRedundantCheck
             if (cmd_node && cmd_node->location_in_or_at_end_of_source_range(pos)) {
                 // Complete command filename.
                 completer.complete_cmd(current_token, use_function, use_builtin, use_command,

src/env_universal_common.cpp

@@ -1059,7 +1059,6 @@ class universal_notifier_shmem_poller_t : public universal_notifier_t {
 
         // Read the current seed.
         this->poll();
-        // cppcheck-suppress memleak // addr not really leaked
     }
 
    public:

src/parse_tree.cpp

@@ -127,7 +127,6 @@ const wchar_t *token_type_description(parse_token_type_t type) {
     // This leaks memory but it should never be run unless we have a bug elsewhere in the code.
     const wcstring d = format_string(L"unknown_token_type_%ld", static_cast<long>(type));
     wchar_t *d2 = new wchar_t[d.size() + 1];
-    // cppcheck-suppress memleak
     return std::wcscpy(d2, d.c_str());
 }
 
@@ -138,7 +137,6 @@ const wchar_t *keyword_description(parse_keyword_t type) {
     // This leaks memory but it should never be run unless we have a bug elsewhere in the code.
     const wcstring d = format_string(L"unknown_keyword_%ld", static_cast<long>(type));
     wchar_t *d2 = new wchar_t[d.size() + 1];
-    // cppcheck-suppress memleak
     return std::wcscpy(d2, d.c_str());
 }