getfreediskspace() - treat unit value of 1 the same as 0 (no need to divide

or shift).

src/xpdev/dirwrap.c

@@ -619,7 +619,7 @@ ulong DLLCALL getfreediskspace(const char* path, ulong unit)
 			NULL))		// receives the free bytes on disk
 			return(0);
 
-		if(unit)
+		if(unit>1)
 			avail.QuadPart=Int64ShrlMod32(avail.QuadPart,bit_num(unit));
 
 #if defined(_ANONYMOUS_STRUCT)
@@ -647,7 +647,7 @@ ulong DLLCALL getfreediskspace(const char* path, ulong unit)
 		))
 		return(0);
 
-	if(unit)
+	if(unit>1)
 		NumberOfFreeClusters/=unit;
 	return(NumberOfFreeClusters*SectorsPerCluster*BytesPerSector);
 
@@ -660,7 +660,7 @@ ulong DLLCALL getfreediskspace(const char* path, ulong unit)
     if (statfs(path, &fs) < 0)
     	return 0;
 
-	if(unit)
+	if(unit>1)
 		fs.f_bavail/=unit;
     return fs.f_bsize * fs.f_bavail;