tree-wide: drop !! casts to booleans

They are not needed, because anything that is non-zero is converted
to true.

C11:
> 6.3.1.2: When any scalar value is converted to _Bool, the result is 0 if the
> value compares equal to 0; otherwise, the result is 1.

https://stackoverflow.com/questions/31551888/casting-int-to-bool-in-c-c

src/shared/bus-util.c

@@ -1090,9 +1090,9 @@ static int map_basic(sd_bus *bus, const char *member, sd_bus_message *m, unsigne
                         return r;
 
                 if (flags & BUS_MAP_BOOLEAN_AS_BOOL)
-                        * (bool*) userdata = !!b;
+                        *(bool*) userdata = b;
                 else
-                        * (int*) userdata = b;
+                        *(int*) userdata = b;
 
                 return 0;
         }
@@ -1403,7 +1403,7 @@ int bus_property_set_bool(
         if (r < 0)
                 return r;
 
-        *(bool *) userdata = !!b;
+        *(bool*) userdata = b;
         return 0;
 }
 

src/shared/condition.c

@@ -103,7 +103,7 @@ static int condition_test_kernel_command_line(Condition *c) {
         if (r < 0)
                 return r;
 
-        equal = !!strchr(c->parameter, '=');
+        equal = strchr(c->parameter, '=');
 
         for (p = line;;) {
                 _cleanup_free_ char *word = NULL;

src/shared/conf-parser.c

@@ -632,7 +632,7 @@ int config_parse_bool(const char* unit,
                 return fatal ? -ENOEXEC : 0;
         }
 
-        *b = !!k;
+        *b = k;
         return 0;
 }