At the beginning of the Parsha (47:29-31) Yosef alone is instructed
briefly by Yaakov to not allow Yaakov to be buried in Egypt and to carry
him out of Egypt for burial with his forefathers. Yaakov makes no mention
to Yosef of Eretz C'na'an, Efron or Meoras Hamachpelah. Much later, after
all the brachos, Yaakov instructs all of the brothers, including Yosef, in
great detail that he is to be buried in Meoras Hamachpelah acquired from
Efron in Eretz C'na'an. (49:29-32)
It is clear that Yaakov is giving two sets of instructions concerning his
burial. The first set is for Yosef only. Yosef, who has the power to do
so, is tasked with making sure Yaakov is able to be brought out of Egypt.
Once Yosef achieves this goal he has the same instructions as all of the
brothers, namely, to bring Yaakov from the Egyptian border to Eretz
C'na'an to Meoras Hamachpelah. This is why Yaakov emphasized to Yosef
getting him out of Egypt while emphasizing, separately, to the brothers
about Meoras Hamachpelah.
This also neatly explains why the psukim separately account for Yosef and
the brothers as having followed Yaakov's directions. First Yosef alone
deals with getting him out of Egypt (50:4-8; see especially 50:7 "And
Yosef went up to bury his father…"). Later, after the events of Goren
Ha'atad, all the brothers carry him to Eretz C'na'an and Meoras
Hamachpelah (50:12-13; see especially 50:12 " And his sons did for him as
he had commanded them to do.").
[This is based on a shiur of HoRav Yochanan Zweig, Shlita.]