Swap: fix code smells

Author: CarterLi

src/detection/swap/swap_haiku.c

@@ -2,16 +2,14 @@
 
 #include <OS.h>
 
-enum { FFMaxNSwap = 8 };
-
 const char* ffDetectSwap(FFSwapResult* swap)
 {
     system_info info;
     if (get_system_info(&info) != B_OK)
         return "Error getting system info";
 
-    swap->bytesTotal = B_PAGE_SIZE * info.max_swap_pages;
-    swap->bytesUsed = B_PAGE_SIZE * (info.max_swap_pages - info.free_swap_pages);
+    swap->bytesTotal = B_PAGE_SIZE * (uint64_t) info.max_swap_pages;
+    swap->bytesUsed = B_PAGE_SIZE * (uint64_t) (info.max_swap_pages - info.free_swap_pages);
 
     return NULL;
 }

src/detection/swap/swap_linux.c

@@ -7,7 +7,7 @@
 
 const char* ffDetectSwap(FFSwapResult* swap)
 {
-    // #620
+    // Ref: #620
     char buf[PROC_FILE_BUFFSIZ];
     ssize_t nRead = ffReadFileData("/proc/meminfo", ARRAY_SIZE(buf) - 1, buf);
     if(nRead < 0)