Correct attributes for swab()

cfg/posix.cfg

@@ -3572,6 +3572,7 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
       <not-uninit/>
     </arg>
   </function>
+  <!-- void swab(const void * src, void* dest, ssize_t bytes); -->
   <function name="swab">
     <returnValue type="void"/>
     <noreturn>false</noreturn>
@@ -3581,10 +3582,8 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     </arg>
     <arg nr="2">
       <not-null/>
-      <not-uninit/>
     </arg>
     <arg nr="3">
-      <not-null/>
       <not-uninit/>
     </arg>
   </function>