hmm... this is an interesting one.
Well ok. For starters. The codex does not specify that the either E. Storm, or Mind War are shooting psychic attacks. Thus one could argue that E. Storm does not require line of sight (Mind War, however, specifically states that it requires ling of sight).
BUT. The Eldar FAQ that was released for 5th edition explicitly states in answer to "which Eldar Psychic powers are psychic shooting attacks":
"A: Destructor, Eldritch Storm, and Mind War"
However, they then have a blurb in parentheses,
"(Though they include a few exceptions to the normal shooting rules, as specified in their description.)"
So to conclude. Eldritch Storm is a shooting attack. However it's apparent that both RAI and RAW show that GW specifies the manner in which Eldritch Storm is fired, and it does not scatter. It is merely placed, as written in the codex.
But wait. It gets even better. The heading just above the description of all the psychic powers on page 28 states:
"Unless otherwise noted, these powers work as described in the psychic powers section of the warhammer 40,000 rulebook, are used at the start of the Eldar turn and do not require the Eldar psyker to have line of sight to target."
So, to further the point, as it does not "otherwise note" the power Eldritch storm also does not require line of sight to its target, and can therefore be used inside vehicles that do not have fire points, unlike Mind War (which requires LoS per it's own rules), and Destructor (which specifically states it is fired like a normal shooting attack).
Good Hunting,
-Stezerok