Fixed a typo

"am broadcast -a" rather than "am broadcast am"
Bug: 123230379
Test: commands #4 and #5 in bug report

Change-Id: I5c23cd86b4da1e03b65c9a68a3a9044466012e89
diff --git a/cmds/screencap/screencap.cpp b/cmds/screencap/screencap.cpp
index 4410f1c..bb32dd2 100644
--- a/cmds/screencap/screencap.cpp
+++ b/cmds/screencap/screencap.cpp
@@ -105,7 +105,7 @@
     char *cmd[] = {
         (char*) "am",
         (char*) "broadcast",
-        (char*) "am",
+        (char*) "-a",
         (char*) "android.intent.action.MEDIA_SCANNER_SCAN_FILE",
         (char*) "-d",
         &filePath[0],