[nit] Fix buggy indentation

The bug was reported by Dan Carpenter and found by Smatch static
checker.

https://lore.kernel.org/all/20211008063704.GA5370@kili/

lib/compress/zstd_lazy.c

@@ -1985,7 +1985,7 @@ size_t ZSTD_compressBlock_lazy_extDict_generic(
                 matchLength = ml2, start = ip, offset=offsetFound;
         }
 
-         if (matchLength < 4) {
+        if (matchLength < 4) {
             ip += ((ip-anchor) >> kSearchStrength) + 1;   /* jump faster over incompressible sections */
             continue;
         }