Apply suggestions from code review

Co-authored-by: Michael Grund <23025878+michaelgrund@users.noreply.github.com>

pygmt/src/xyz2grd.py

@@ -137,12 +137,12 @@ def xyz2grd(data=None, x=None, y=None, z=None, **kwargs):
     >>> import pygmt  # doctest: +SKIP
     >>> # Load a sample bathymetry file
     >>> sample_bathymetry = (
-    ...     pygmt.datasets.load_sample_bathymetry()
+    ...     pygmt.datasets.load_sample_data(name="bathymetry")
     ... )  # doctest: +SKIP
     >>> # Create a new grid from the xyz input, set the x-range to 245-255 and
     >>> # the y-range to 20-30, and the spacing to 5 degrees
     >>> new_grid = pygmt.xyz2grd(
-    ...     data=ship_data, spacing=5, region=[245, 255, 20, 30]
+    ...     data=sample_bathymetry, spacing=5, region=[245, 255, 20, 30]
     ... )  # doctest: +SKIP
     """
     with GMTTempFile(suffix=".nc") as tmpfile: