mount seems like an incorrect value for the first field in your fstab and looks like you simply copied a
man 5 fstab) ... The first field in
/etc/fstab, (fs_spec), describes the block special device or remote filesystem to be mounted. For ordinary mounts it will hold (a link to) a block special device node (as created by mknod(8)) for the device to be mounted, like
For NFS mounts one will have :, e.g., ‘knuth.aeb.nl:/’.
I would expect something like this instead in /etc/fstab:
//sambashare /media/sambashare cifs credentials=/etc/smbcredentials,iocharset=utf8,sec=ntlm,_netdev
_netdev mount option is strongly recommended, it will delay mounting file-systems that require network access until after the network connection has been established, preventing time-outs.