faultspaceplot: don't round down ymin

Before this change, ymin was rounded down to the nearest Y value
divisible by 1000, showing an empty, white area in the lower part of
the plot.  With this change, the initial Y-axis zoom level is
maximized to exactly show all non-white areas.

Change-Id: I1aea52a3afc331e7f11fe76ff2c5de3c71c61c71

tools/analysis/faultspaceplot/fsp.plot.py

@@ -106,7 +106,8 @@ for row in reader:
         pass
         #break
 
-ymin = int(ymin / 1000) * 1000
+# round down to nearest 1000
+#ymin = int(ymin / 1000) * 1000
 
 file.close()
 plt.xlim(xmin, xmax)