Revert "examples/cg/cg_kernels.c: lower default value when running with"

This reverts commit 22ed8fd5b1db38a07871776fa0eaa6e1a4d1b58c.

This is not supposed to be very long, it seems that it sometimes hangs.
We'd rather check a few iterations anyway.

examples/cg/cg_kernels.c

@@ -34,7 +34,7 @@ static const TYPE gm1 = -1.0;
 static int nblocks = 8;
 
 #ifdef STARPU_QUICK_CHECK
-static int i_max = 2;
+static int i_max = 5;
 static int long long n = 2048;
 #elif !defined(STARPU_LONG_CHECK)
 static int long long n = 4096;