The ornamental design for a holster mount, as shown and described.
FIG. 1 is a rear side perspective view of a holster mount showing my new design, comprising a clip and bracket coupled to a holster; the broken lines showing the portions of the design, which form no part of the claim;
FIG. 2 is a rear elevation view thereof;
FIG. 3 is a rear perspective view of the clip portion of the holster mount coupled to the holster, the bracket removed for ease of illustration;
FIG. 4 is a rear perspective view of the mounting bracket; the clip and holster removed for ease of illustration; and,
FIG. 5 is a front perspective view of the mounting bracket of FIG. 4.
In FIGS. 1-5, the broken lines represent the portions of the design that form no part of the claim.