qdutils: Pre-allocate initial buffer for getline().

Some frameworks override malloc() and free() but not getline().
Pre-allocating the buffer avoids heap mismatch on free().

Change-Id: I9bd934f701ad7dbc10ec2aa21967e2a626c496f4
diff --git a/libqdutils/mdp_version.cpp b/libqdutils/mdp_version.cpp
index 9e36980..fc5d1d0 100644
--- a/libqdutils/mdp_version.cpp
+++ b/libqdutils/mdp_version.cpp
@@ -149,7 +149,7 @@
 // and parses and updates information accordingly.
 bool MDPVersion::updateSysFsInfo() {
     FILE *sysfsFd;
-    size_t len = 0;
+    size_t len = PAGE_SIZE;
     ssize_t read;
     char *line = NULL;
     char sysfsPath[255];
@@ -172,6 +172,7 @@
                 __FUNCTION__, sysfsPath);
         return false;
     } else {
+        line = (char *) malloc(len);
         while((read = getline(&line, &len, sysfsFd)) != -1) {
             int index=0;
             char *tokens[10];
@@ -221,9 +222,8 @@
                     }
                 }
             }
-            free(line);
-            line = NULL;
         }
+        free(line);
         fclose(sysfsFd);
     }
     ALOGD_IF(DEBUG, "%s: mMDPVersion: %d mMdpRev: %x mRGBPipes:%d,"