libs/utils: replace malloc() + memset() to zero with calloc()

Change-Id: I8bdf4360147e51e35c162856c9a859aed6acac34
Signed-off-by: Iliyan Malchev <malchev@google.com>
diff --git a/libs/utils/BackupHelpers.cpp b/libs/utils/BackupHelpers.cpp
index f77a891..214f6d7 100644
--- a/libs/utils/BackupHelpers.cpp
+++ b/libs/utils/BackupHelpers.cpp
@@ -546,7 +546,7 @@
 
     // read/write up to this much at a time.
     const size_t BUFSIZE = 32 * 1024;
-    char* buf = new char[BUFSIZE];
+    char* buf = (char *)calloc(1,BUFSIZE);
     char* paxHeader = buf + 512;    // use a different chunk of it as separate scratch
     char* paxData = buf + 1024;
 
@@ -556,9 +556,6 @@
         goto cleanup;
     }
 
-    // Good to go -- first construct the standard tar header at the start of the buffer
-    memset(buf, 0, BUFSIZE);
-
     // Magic fields for the ustar file format
     strcat(buf + 257, "ustar");
     strcat(buf + 263, "00");