consensus/ethash: remove temp files created during DAG generation (ethereum#25381)

This makes it remove not only the actual DAG file, but also the temporary file
which the DAG data is written to while generating.

Author: manoj398

consensus/ethash/ethash.go

@@ -278,8 +278,11 @@ func (c *cache) generate(dir string, limit int, lock bool, test bool) {
 		// Iterate over all previous instances and delete old ones
 		for ep := int(c.epoch) - limit; ep >= 0; ep-- {
 			seed := seedHash(uint64(ep)*epochLength + 1)
-			path := filepath.Join(dir, fmt.Sprintf("cache-R%d-%x%s", algorithmRevision, seed[:8], endian))
-			os.Remove(path)
+			path := filepath.Join(dir, fmt.Sprintf("cache-R%d-%x%s*", algorithmRevision, seed[:8], endian))
+			files, _ := filepath.Glob(path) // find also the temp files that are generated.
+			for _, file := range files {
+				os.Remove(file)
+			}
 		}
 	})
 }