[PATCH] example-app: Fix a compile warning in patched example

[Henning Schild <henning.schild@siemens.com>]

One of the patches introduced in a8ecb2bd3367 triggers a compiler
warning because of a missing prototype for "strcmp". Include string.h to
solve that problem.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
---
 .../example-hello/files/0001-Add-some-help.patch            | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/meta-isar/recipes-app/example-hello/files/0001-Add-some-help.patch b/meta-isar/recipes-app/example-hello/files/0001-Add-some-help.patch
index 3c68a93..f134077 100644
--- a/meta-isar/recipes-app/example-hello/files/0001-Add-some-help.patch
+++ b/meta-isar/recipes-app/example-hello/files/0001-Add-some-help.patch
@@ -1,4 +1,4 @@
-From 4615f473881aaff12a52aa3bb625bfb38753b4f2 Mon Sep 17 00:00:00 2001
+From 2bf0be78037bb3140a4af5ec3755960a278e84cf Mon Sep 17 00:00:00 2001
 From: Jan Kiszka <jan.kiszka@siemens.com>
 Date: Sun, 18 Feb 2018 09:02:11 +0100
 Subject: [PATCH] Add some help
@@ -7,18 +7,19 @@ This just provides a commit to demonstrate patching in Isar recipes.
 
 Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
 ---
- hello.c | 11 ++++++++++-
- 1 file changed, 10 insertions(+), 1 deletion(-)
+ hello.c | 12 +++++++++++-
+ 1 file changed, 11 insertions(+), 1 deletion(-)
 
 diff --git a/hello.c b/hello.c
-index 269c24b..329a0c5 100644
+index 269c24b..941babc 100644
 --- a/hello.c
 +++ b/hello.c
-@@ -5,10 +5,19 @@
+@@ -5,10 +5,20 @@
   * version 2.
   */
  
 +#include <stdio.h>
++#include <string.h>
  #include <hello.h>
  
 -int main(void)
@@ -36,5 +37,5 @@ index 269c24b..329a0c5 100644
  	return 0;
  }
 -- 
-2.13.6
+2.16.4
 
-- 
2.16.4