spreadlevel-plot: Fix missing #include <stdlib.h>

Reported by GCC:

spreadlevel-plot.c: In function ‘spreadlevel_plot_chart_destroy’:
spreadlevel-plot.c:84: error: implicit declaration of function
‘free’
preadlevel-plot.c:84: error: incompatible implicit declaration of
built-in function ‘free’

diff --git a/src/output/charts/spreadlevel-plot.c b/src/output/charts/spreadlevel-plot.c
index 8fcc0bdeebfa8856accf15ae6e1e3e7974526084..d5b6e3d01a33aa483f6968fd9493a9fffca30a2a 100644 (file)
--- a/src/output/charts/spreadlevel-plot.c
+++ b/src/output/charts/spreadlevel-plot.c
@@ -26,6 +26,7 @@
 
 #include <math.h>
 #include <float.h>
+#include <stdlib.h>
 
 struct chart_item *
 spreadlevel_plot_create (const char *label, double tx_pwr)