lib: Remove misplaced and redundant comments

It's obvious that unsigned long long is 64 bit and also our web page
generator would misplace the comment after the return value due to the
way it's parsing them.

src/libvirt-domain.c

@@ -5820,7 +5820,7 @@ virDomainMemoryStats(virDomainPtr dom, virDomainMemoryStatPtr stats,
 int
 virDomainBlockPeek(virDomainPtr dom,
                    const char *disk,
-                   unsigned long long offset /* really 64 bits */,
+                   unsigned long long offset,
                    size_t size,
                    void *buffer,
                    unsigned int flags)
@@ -5956,7 +5956,7 @@ virDomainBlockResize(virDomainPtr dom,
  */
 int
 virDomainMemoryPeek(virDomainPtr dom,
-                    unsigned long long start /* really 64 bits */,
+                    unsigned long long start,
                     size_t size,
                     void *buffer,
                     unsigned int flags)